Bone graft applicator

ABSTRACT

A method for applying bone graft to an orthopaedic implant. The method includes using a bone graft applicator including a pair of arms, a bone graft receptacle coupled to the arms, and a linking mechanism coupled to the bone graft receptacle. The linking mechanism is slid over a portion of the orthopaedic implant. Bone graft is scraped into the bone graft receptacle. The user closes the bone graft receptacle over the portion of the orthopaedic implant and then removes one of the bone graft applicator and the orthopaedic implant from the other of the bone graft applicator and the orthopaedic implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Utility patentapplication Ser. No. 12/860,487 entitled “Bone Graft Applicator”, filedon Aug. 20, 2010 by Sarah M. Anthony and claims benefit to U.S.Provisional Patent Application Ser. No. 61/354,324 entitled “Bone GraftApplicator” filed on May 17, 2010. Each of these are expresslyincorporated herein by reference in their entireties

TECHNICAL FIELD

The present invention relates generally to an instrument for use inorthopaedic surgery, and more particularly to an instrument for graftingbone onto an orthopaedic implant.

BACKGROUND

During the lifetime of a patient, it may be necessary to perform a totalshoulder replacement procedure on the patient as a result of, forexample, disease or trauma. In a total shoulder replacement procedure, ahumeral component having a head portion is utilized to replace thenatural head portion of the arm bone or humerus. The humeral componenttypically has an elongated intramedullary stem that is utilized tosecure the humeral component to the patient's humerus. In such a totalshoulder replacement procedure, the natural glenoid surface of thescapula is resurfaced or otherwise replaced with a glenoid componentthat provides a bearing surface for the head portion of the humeralcomponent.

In response to shortcomings associated with two-piece glenoid componentdesigns, a number of one-piece glenoid components have heretofore beendesigned. In regard to such one-piece designs, a body portion, having abearing surface defined therein for receiving the head of the humeralcomponent, has a number of attachment pegs integrally formed therewith.The attachment pegs are advanced and thereafter secured into acorresponding number of holes that are drilled in the glenoid surface ofthe scapula by use of bone cement. An example of such a one-pieceglenoid component that is designed to be secured to the scapula by useof bone cement is disclosed in U.S. Pat. No. 5,032,132 issued to Matsen,III et al.

Certain one-piece glenoid components have been designed to includefinned-pegs, such as described in U.S. Pat. No. 6,911,047, which isherein incorporated by reference in its entirety. The fins act as barbswhen the pegs are inserted into holes drilled in the scapula, securingthe glenoid component to the scapula.

In some methods of inserting the finned-peg glenoid implant to thescapula, bone graft is inserted between the fins. Adding bone graft aidsin the osseointegration of the implant into the scapula. However, thereis currently not an instrument offered that places the bone graft ontothe implant. Oftentimes, a member of the surgical team will use theirgloved hands to apply the bone graft onto the pegs. However, the bonegraft will often stick to the user's gloves, making this method ofapplying bone graft messy and imprecise.

Therefore, there is a need for an instrument to efficiently andadequately apply bone graft to a glenoid component.

Also, there is a need for an instrument that can efficiently andadequately apply bone graft to other orthopaedic implants.

SUMMARY OF THE INVENTION

According to one embodiment of the present application, a bone graftapplicator for applying bone graft to an orthopaedic implant isprovided. The bone graft applicator includes a pair of arms and a bonegraft receptacle sized and shaped to be able to receive a portion of theorthopaedic implant within the receptacle. The bone graft receptacle iscoupled to each of the pair of arms. The bone graft applicator furtherincludes a linking mechanism, the linking mechanism including a recesssized and shaped to extend at least partially around the portion of theorthopaedic implant, the linking mechanism coupled to the bone graftreceptacle.

According to another embodiment of the present invention, a method forapplying bone graft to an orthopaedic implant is provided. The methodincludes using a bone graft applicator including a pair of arms, a bonegraft receptacle coupled to the arms, and a linking mechanism coupled tothe bone graft receptacle. The linking mechanism is slid over a portionof the orthopaedic implant and bone graft is scraped into the bone graftreceptacle. The bone graft receptacle is closed over the portion of theorthopaedic implant. The bone graft applicator is removed from theorthopaedic implant.

According to yet another embodiment of the present invention, a kit forapplying bone graft is provided and includes a glenoid component havinga peg and a bone graft applicator. The bone graft applicator is sizedand shaped to apply bone graft to the peg of the glenoid component. Thebone graft applicator includes a pair of arms, a pair of cavitiescoupled to the pair of arms, and a linking mechanism coupled to the pairof cavities. The pair of cavities can be in an opened position such thatone of the pair of cavities is located at an angle from the other of thepair of cavities and the angle is in the range of about 100 degrees toabout 180 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptiontaken in connection with the accompanying drawings.

FIG. 1 is an exploded perspective view that shows a glenoid componentpositioned between a glenoid surface of a scapula and a humeralcomponent.

FIG. 2 is a perspective view of the glenoid component of FIG. 1.

FIG. 3 is a perspective view of a bone graft applicator according to oneembodiment of the present application in an open position.

FIG. 4 is a perspective view of a bone graft applicator of FIG. 3 in aclosed position.

FIG. 5 is a flow chart illustrating the method of operating the bonegraft applicator of FIG. 3.

FIG. 6 is a perspective view of the bone graft applicator of FIG. 3 anda glenoid component of FIG. 1 in use.

FIG. 7 is a perspective view of the bone graft applicator of FIG. 3applying bone graft to the glenoid component of FIG. 1.

FIG. 8 is a perspective view of the bone graft applicator of FIG. 3after it has been removed from the glenoid component of FIG. 1.

FIG. 9 is a perspective view of a bone graft applicator according toanother embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention and the advantages thereof are bestunderstood by referring to the following descriptions and drawings,wherein like numerals are used for like and corresponding parts of thedrawings.

Referring now to FIG. 1, there is shown a glenoid component 10 locatedbetween a glenoid surface 12 of a scapula 14 and a humeral component 16.The humeral component 16 has been implanted or otherwise secured to ahumerus 18. As shall be discussed below in greater detail, the glenoidcomponent 10 is configured to be secured to the glenoid surface 12 ofthe scapula 14 without the use of bone cement on an anchor peg 28(discussed below) in order to replace the natural glenoid surface 12during a total shoulder replacement procedure. In such a manner, theglenoid component 10 functions as a bearing surface for receiving a headportion of the humerus 18 (i.e. a head portion 20 of the humeralcomponent 16 implanted in the humerus 18).

As shown in FIGS. 1 and 2, the glenoid component 10 includes a bodyportion 22 having a first generally convex surface 24 and a secondgenerally concave surface 26. The convex surface 24 is configured toabut or otherwise contact the glenoid surface 12 of the scapula 14 whenthe glenoid component 10 is secured thereto. The concave surface 26 ofthe body portion 22 provides a bearing surface for the head portion 20of the humeral component 16 implanted into the humerus 18.

The glenoid component also includes the anchor peg (or central peg) 28and a number of stabilizing pegs 30, 32, 34. The anchor peg 28 and thestabilizing pegs 30, 32, 34 are secured to the convex surface 24 of thebody portion 22 and extend outwardly therefrom. As shown in FIG. 1, theanchor peg 28 is received into an anchor hole 38 which is drilled orotherwise formed in the glenoid surface 12 of the scapula 14, whereasthe stabilizing pegs 30, 32, 34 are received into a number of respectivestabilizing holes 40, 42, 44 which are also drilled or otherwise formedin the glenoid surface 12 of the scapula 14.

The anchor peg 28 includes a beveled shaft portion 46 that is secured atits proximal end to the convex surface 24. The distal end portion of theshaft portion 46 has a conical tip 48 defined therein which is providedas a “lead in” to facilitate insertion of the anchor peg 28 into theanchor hole 38 drilled in the glenoid surface 12 of the scapula 14.

In addition to the conical tip 48, the distal end portion of the shaftportion 46 also has a number of fins 50 (or flutes) secured thereto. Thefins 50 extend radially outwardly from the shaft portion 46 of theanchor peg 28 in a substantially perpendicular direction relative to theshaft portion 46 such that the outer diameter of each of the fins 50 isgreater than the outer diameter of the shaft portion 46. Each of thefins 50 preferably extends continuously around the entire outerperiphery of the shaft portion 46, although the fins 50 mayalternatively be embodied as a series of individual flange sections thatline substantially all of the outer periphery of the shaft portion 46.

As discussed above in the Background section, some surgeons desire toplace bone graft onto the fins 50 and into the spaces between the fins50 to aid in the bone integration of the implant. The bone graft may betaken from a number of places. In some embodiments, the bone graft istaken from drilling the anchor hole 38 of the glenoid. In otherembodiments, it is taken from drilling the resected portion of thehumeral head. To aid in this, according to one aspect of the invention,a bone graft applicator (or instrument) 60 is provided as shown in FIGS.3 and 4. As shown, the bone graft applicator 60 includes a pair of arms62, 64. The pair of arms 62, 64 are coupled via a linking mechanism 66.In this embodiment, the linking mechanism 66 is a ring 68. The ring 68includes a recess 70 that is sized and shaped to receive the fins 50 ofthe glenoid component 10. In this embodiment, the linking mechanism 66is sized and shaped to slide over and around the portion of the implantthat is to receive the bone graft. In other embodiments, the linkingmechanism 66 may extend only partially around the portion of the implantthat is to receive the bone graft. In yet other embodiments, the linkingmechanism 66 may not be able to slide over the portion of the implant,but may still extend partially around that portion. As shown in FIGS. 3and 4, each of the arms 62, 64 includes a handle 72, 74. The handles 72,74 allow the user to grasp the applicator 60. In some embodiments, thehandles 72, 74 may not be included and the user may grasp the arms 62,64.

As shown in FIG. 3, the arms 62, 64 are coupled to a bone graftreceptacle 75. In the illustrated embodiment, the bone graft receptacle75 includes a pair of cavities 76, 78. The cavities 76, 78 are coupledto and adjacent to the linking mechanism 66. The cavities 76, 78 areeach linked to the linking mechanism 66 via a hinge 79. The hinge allowsthe cavities 76, 78 (and thus the arms 62, 64) to open and close asshown in FIGS. 3 and 4. Specifically, the hinge 79 allows the cavities76, 78 (and thus arms 62, 64) to open to a large angle α (defined as theangle between the two arms 62, 64). In one embodiment, the angle α isbetween about 100 and about 180 degrees. Preferably, the angle α isbetween about 170 and about 180 degrees. By having the arms opened wide,the cavities 76, 78 are easier to fill with the bone graft. The cavities76, 78 are sized and shaped to receive the bone graft. When the arms arein a closed position as shown in FIG. 4, the cavities 76, 78 create asingle cavity that is sized and shaped to receive the anchor peg 28 (aswill be shown in FIG. 7 below).

Turning now to FIGS. 5-8, a flow chart illustrating the method of usingthe bone graft applicator 60 is shown. First, at step s100, the bonegraft applicator 60 is slid over the anchor peg 28, which may be sittingon a table with the articular surface down and anchor peg 28 up. Thearms 62, 64 of the applicator 60 are then opened as shown in FIG. 6 atstep s102, exposing the fins 50. In some embodiments, the applicator maybe in an open position prior to being slid over the anchor peg. As shownin FIG. 6, the ring 68 slides over (and thus extends around) the anchorpeg 28 and fins 50. In other words, the recess 70 (which is in thisembodiment, a circular opening) is slid over the anchor peg 28. Next, atstep s104, the bone graft (also known as bone paste) is scraped into thecavities 76, 78. The bone graft should be placed into both cavities 76,78. In the illustrated embodiment, as shown in FIG. 6, an instrument 80holds bone graft 82. A scraper 84 is used to scrape the bone graft 82out of the instrument 80 and into the cavities 76, 78 of the bone graftapplicator 60. In other embodiments, other tools or methods for applyingthe bone graft to the cavities 76, 78 may be used.

At step s106, the bone graft applicator 60 is closed over the anchor peg28 and its fins 50 (shown in FIG. 7). The two cavities 76, 78 surroundthe anchor peg 28 and apply the bone graft 82 in between the fins 50. Inthe present embodiment, the bone graft applicator 60 applies the bonegraft equally to both sides simultaneously. The two cavities 76, 78surround the peg at the same time, are perpendicular to the ground, andare equally affected by the effects of gravity, thereby applying thebone graft equally (and simultaneously) around the peg 28. The bonegraft applicator is then rotated about the anchor peg 28 in thedirection shown by arrows 86 in FIG. 7 at step s108 while the anchor peg28 is held in place (to keep from rotating). The rotation further embedsthe bone graft 82 in between the fins 50. With the bone graft applicator60 still in a closed position, the bone graft applicator is then removedfrom the anchor peg 28 (step s110). As shown in FIG. 8, bone graft 82fills in the space between the fins 50. Removal of the bone graftapplicator is easy since the bone graft applicator 60 is kept closed.Also, since the cavities 76, 78 are closed, any bone graft 82 that isnot affixed to the fins 50 is less likely to spill out of the applicator60. Furthermore, removal along the axis as indicated by the arrow 88compresses the bone graft 82 into the fins 50 and prevents migration ofthe bone graft 82 out of the sides of the fins 50.

Turning now to FIG. 9, another embodiment of a bone graft applicator 110will be described. In this embodiment, the bone graft applicator 110includes a pair of arms 112, 114. The pair of arms 112, 114 are coupledvia a linking mechanism 116. In this embodiment, the linking mechanism116 is a pair of rods 118, 120 and a u-shaped wall 124 and an arcuatewall 126. The pair of rods 118, 120 extends from one arm 112, 114 into arecess on the other arm 112, 114 (not shown). The u-shaped wall 124 andarcuate wall 126 also define the bone graft receptacle 125. In thisembodiment, the bone graft receptacle includes a shaped cavity 122. Thearm 112 also includes two channels 130, 132 that receive the ends of theu-shaped wall 124. In use, the user will place the anchor peg 28 (FIGS.1 and 2) into the applicator 110. After the bone graft is poured intothe cavity 122, the two arms 112, 114 are slid together, causing theends of the u-shaped wall 124 to slide into the channels 130, 132 anddecrease the size of the shaped cavity 122. The bone graft is thenforced into the fins 50 as the arcuate wall 126 comes closer to the endof the u-shaped wall 124. By moving the arms 112, 114, the bone-shapedcavity is then sized and shaped to abut the fins 50 on the anchor peg 28and to apply the bone graft into the fins 50. In the illustratedembodiment, the arms 112, 114 of the applicator 110 include handles 134,136. In some embodiments, there may not be handles, and the user mayjust grasp the arms.

In some embodiments, the applicators 60, 110 may be made of stainlesssteel. In other embodiments, the applicators 60, 110 may be made ofplastic. Other materials may also be used. As shown in the embodimentsof FIGS. 1-4 and 6-8, each of the cavities 76, 78 and each of the arms62, 64, 112 and 114 are a single piece. However, in other embodiments,the cavity and the arms may be separate pieces and may be coupled usingany known method.

The above embodiments both describe using the bone graft applicator toapply bone graft to a peg on a glenoid component. However, the bonegraft applicator may also be used to apply bone graft to pegs located onknee implants, such as a patellar component, a femoral component, or atibial component. In each of these cases, the linking mechanism of thebone graft applicator should include a recess large enough to be able toextend around the peg. Also, the cavities of such a bone graftapplicator would be sized and shaped to accommodate peg of the implant.The applicator of the present invention may also be used on otherorthopaedic components such as acetabular hip cups, cement plugs, orother pegged implants. In some embodiments, the pegs of the implants maynot be finned (in other words, do not include fins). In these cases, ifthe peg includes a porous coating, the bone graft would be able to stickto the porous coating.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions, andalterations could be made therein without departing from the spirit andscope of the present invention as defined by the appended claims.

We claim:
 1. A method for applying bone graft to an orthopaedic implant,the method comprising: using a bone graft applicator including a pair ofarms, a bone graft receptacle coupled to the arms, and a linkingmechanism coupled to the bone graft receptacle; sliding the linkingmechanism over a portion of the orthopaedic implant; scraping bone graftinto the bone graft receptacle; closing the bone graft receptacle overthe portion of the orthopaedic implant; and removing one of the bonegraft applicator and the orthopaedic implant from the other of the bonegraft applicator and the orthopaedic implant.
 2. The method of claim 1,wherein the portion of the orthopaedic implant is a finned peg andsliding the linking mechanism includes sliding the linking mechanismover the peg and the method further includes rotating the bone graftapplicator around the peg.
 3. The method of claim 1, further comprisingopening the arms of the bone graft applicator after the linkingmechanism has been slid over the portion of the orthopaedic implant. 4.The method of claim 1, wherein the step of removing the bone graftapplicator includes leaving the bone graft applicator in a closedposition while removing the bone graft applicator.
 5. The method ofclaim 1, wherein the bone graft receptacle includes a pair of cavities,one of the pair of cavities integrally formed with one of the pair ofarms and the other of the cavities integrally formed with the other ofthe pair of arms.
 6. The method of claim 5, wherein the method comprisessimultaneously closing the pair of cavities around the portion of theorthopaedic implant and wherein the pair of cavities is heldperpendicular to the ground, such that both cavities equally feel theeffect of gravity.